Mercury and Autism

Claire Gilmore

January 19, 2017

Photo: Charlene Croft

Two new international studies in the journal Metabolic Brain Disease have validated the link between mercury and autism.

In the first study, a team of nine scientists from leading Egyptian universities and medical schools studied children with Autism Spectrum Disorder (ASD) along with control groups of healthy individuals and healthy siblings of ASD children. They measured blood levels of mercury and lead as well as urinary excretion of biomarkers for mercury toxicity, and found that children with the highest mercury levels had the most severe autism symptoms.

The second study, published in June 2016, saw an international team of physicians and scientists show a positive linear relationship between mercury levels and the severity of autism symptoms.

At least six American studies have linked autism presence or severity to mercury exposure. And in November, Robert F. Kennedy, Jr. reported that the two newest studies are “only the latest in a series of leading Egyptian doctors and scientists linking mercury exposure to autism.”

Muskrat Falls

These findings underscore the concerns of communities downstream from the Muskrat Falls dam in Labrador. In November 2012, Nunatsiavut, the Inuit government of northern Labrador, partnered with Harvard University and others to begin research on methylmercury and the unique environment of the area. The Harvard team’s research suggested methylmercury levels could rise as much as 380 per cent if only partial clearing takes place in the reservoir.

First Nations communities in the area fear having their traditional sources of food poisoned for generations to come. Patrick McCully explains in his book Silenced Rivers: The Ecology and Politics of Large Dams, “Mercury is naturally present in a harmless inorganic form in many soils. Bacteria feeding on the decomposing matter under a new reservoir, however, transform this inorganic mercury into methylmercury, a central nervous system toxin. The methylmercury is absorbed by plankton and other creatures at the bottom of the aquatic food chain. As the methylmercury passes up the food chain it becomes increasingly concentrated in the bodies of the animals eating contaminated prey.”

Crown energy corporation Nalcor began the first phase of reservoir flooding in November 2016, following protests, hunger strikes, and occupation of the site by Innu, Inuit and settler Labradorians. A number of land protectors were arrested. The campaign’s central demand was full clearing of the site prior to reservoir flooding to reduce the amount of organic matter that produces methylmercury as it breaks down.

The partial reservoir flooding was deemed necessary ahead of winter freeze up to protect the integrity of the hydro infrastructure. Indigenous leaders gave their approval, although vigils continued.

The Newfoundland and Labrador Independent reported on Nov. 18, 2016 that the provincial government and Innu leaders had agreed that water levels in the reservoir would be lowered in the spring, after which a new Independent Expert Advisory Committee will study the issue. Since then, land protectors have reignited protests because, as reported in theindependent.ca: “they say … they have lost faith in Nalcor and the provincial government’s commitment to protect local’s health and way of life and to respect Indigenous rights and the government’s prior commitment to reconciliation.”